mers/examples/thread.mers

// this is true by default so the example doesn't finish too quickly or too slowly depending on your hardware.
// you can set it to false and tweak the max value for a more authentic cpu-heavy workload.
fake_delay = true

// this will be shared between the two threads to report the progress in percent (0-100%).
progress = 0

// an anonymous function that sums all numbers from 0 to max.
// it captures the progress variable and uses it to report its status to the main thread, which will periodically print the current progress.
// once done, it returns a string with the sum of all numbers.
calculator = (max int) {
    sum = 0
    for i max {
        i = i + 1
        // println("i: {0} s: {1}".format(i.to_string() sum.to_string()))
        &sum = sum + i
        if fake_delay sleep(1)
        &progress = i * 100 / max
    }
    "the sum of all numbers from 0 to {0} is {1}!".format(max.to_string() sum.to_string())
}

// start the thread. if fake_delay is true, calculate 1+2+3+4+5+6+7+8+9+10. if fake_delay is false, count up to some ridiculously large number.
slow_calculation_thread = calculator.thread(if fake_delay 10 else 20000000)

// every second, print the progress. once it reaches 100%, stop
loop {
    sleep(1)
    println("{0}%".format(progress.to_string()))
    progress == 100 // break from the loop
}

// use await() to get the result from the thread. if the thread is still running, this will block until the thread finishes.
result = slow_calculation_thread.await()

println("Thread finished, result: {0}".format(result))